rs369246066

Positions:

• chr12-2585502-G-A

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_000719.7(CACNA1C):​c.2460+6G>A variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000448 in 1,552,772 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00029 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00047 (0 hom.)
• Consequence: CACNA1C NM_000719.7 splice_donor_region, intron
• Scores: Splicing: ADA: 0.0003690
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:5
• Conservation: PhyloP100: -0.586

Genes affected

CACNA1C (HGNC:1390): (calcium voltage-gated channel subunit alpha1 C) This gene encodes an alpha-1 subunit of a voltage-dependent calcium channel. Calcium channels mediate the influx of calcium ions into the cell upon membrane polarization. The alpha-1 subunit consists of 24 transmembrane segments and forms the pore through which ions pass into the cell. The calcium channel consists of a complex of alpha-1, alpha-2/delta, beta, and gamma subunits in a 1:1:1:1 ratio. There are multiple isoforms of each of these proteins, either encoded by different genes or the result of alternative splicing of transcripts. The protein encoded by this gene binds to and is inhibited by dihydropyridine. Alternative splicing results in many transcript variants encoding different proteins. Some of the predicted proteins may not produce functional ion channel subunits. [provided by RefSeq, Oct 2012]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.74).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000289 (44/152224) while in subpopulation NFE AF= 0.000588 (40/68042). AF 95% confidence interval is 0.000444. There are 0 homozygotes in gnomad4. There are 18 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd4 at 44 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CACNA1C	NM_000719.7	c.2460+6G>A		splice_donor_region_variant, intron_variant		ENST00000399655.6	NP_000710.5
CACNA1C	NM_001167623.2	c.2460+6G>A		splice_donor_region_variant, intron_variant		ENST00000399603.6	NP_001161095.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CACNA1C	ENST00000399603.6	c.2460+6G>A		splice_donor_region_variant, intron_variant		5	NM_001167623.2	ENSP00000382512
CACNA1C	ENST00000399655.6	c.2460+6G>A		splice_donor_region_variant, intron_variant		1	NM_000719.7	ENSP00000382563

Frequencies

GnomAD3 genomes AF: 0.000289 AC: 44 AN: 152224 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000224 AC: 36 AN: 160514 Hom.: 0 AF XY: 0.000272 AC XY: 23 AN XY: 84558

Gnomad AFR exome AF: 0.000108

Gnomad AMR exome AF: 0.0000402

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000497

Gnomad OTH exome AF: 0.000456

GnomAD4 exome AF: 0.000466 AC: 652 AN: 1400548 Hom.: 0 Cov.: 31 AF XY: 0.000446 AC XY: 308 AN XY: 690678

Gnomad4 AFR exome AF: 0.0000310

Gnomad4 AMR exome AF: 0.0000553

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000271

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000585

Gnomad4 OTH exome AF: 0.000293

GnomAD4 genome AF: 0.000289 AC: 44 AN: 152224 Hom.: 0 Cov.: 33 AF XY: 0.000242 AC XY: 18 AN XY: 74364

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000271 Hom.: 0

Bravo AF: 0.000242

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 10, 2023	The CACNA1C c.2460+6G>A variant (rs369246066) is reported in the literature in a sudden infant death cohort, but without clear disease association (Liebrechts-Akkerman 2020). This variant is also reported in ClinVar (Variation ID: 456955), and is found in the general population with an overall allele frequency of 0.020% (39/191908 alleles) in the Genome Aggregation Database. This is an intronic variant and computational analyses (Alamut Visual Plus v.1.5.1) predict that this variant does not alter splicing. However, since this variant is located within the minimal splice region, the clinical significance of this variant is uncertain at this time. References: Liebrechts-Akkerman G et al. Explaining sudden infant death with cardiac arrhythmias: Complete exon sequencing of nine cardiac arrhythmia genes in Dutch SIDS cases highlights new and known DNA variants. Forensic Sci Int Genet. 2020 May;46:102266. PMID: 32145446. -
Likely benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 03, 2015	- -

not specified Benign:2

Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -

Long qt syndrome 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Mar 31, 2022

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3C. Following criteria are met: 0101 - Gain of function is a known mechanism of disease in this gene and is associated with long QT syndrome 8 (MIM #618447), and Timothy syndrome (MIM#601005). Missense variants result in loss of channel inactivation and increased current (OMIM, PMID: 25260352). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0212 - Non-canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v3) <0.001 for a dominant condition (44 heterozygotes, 0 homozygotes). (SP) 0506 - Abnormal splicing is not predicted and nucleotide is poorly conserved. (SB) 0705 - No comparable splice variants have previous evidence for pathogenicity. (I) 0808 - Previous reports of pathogenicity for this variant are conflicting. This variant has been reported as likely benign, benign and as a VUS (LOVD, ClinVar). It was also observed in a SIDS cohort (PMID: 32145446). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 21, 2024

This sequence change falls in intron 17 of the CACNA1C gene. It does not directly change the encoded amino acid sequence of the CACNA1C protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs369246066, gnomAD 0.05%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with CACNA1C-related conditions. ClinVar contains an entry for this variant (Variation ID: 456955). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

CACNA1C-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 05, 2023

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.74
CADD	Benign	7.3
DANN	Benign	0.69

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00037
dbscSNV1_RF	Benign	0.066
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs369246066; hg19: chr12-2694668;